As Eric Asimov wrote in his weekly New York Times column, there is no official definition or doctrine for Natural wine or Natural winemakers. But he offered the following parameters to define Natural wines, noting that they are "wines that are made with an absolute minimum of manipulation: grapes grown organically or in rough approximation, then simply set forth along an unforced path of fermentation into wine, with nothing added and nothing taken away."

Winemakers, wine writers, and wine lovers have inevitably faced the same issue when trying to quantify and articulate Natural wine, a category defined more by what it isn't than what it is.

To my knowledge, there's only one Natural winemaker here in Texas, Lewis Dickson, who grows and vinifies grapes on his Texas Hill Country estate Cruz de Comal, on the south side of Canyon Lake (not far from New Braunfels). The winery takes its name not from the fact that it is located in Comal County but after an iron cross fashioned from comales, traditional Mexican griddles used to make tortillas.

Under the tutelage of legendary California Natural winemaker Tony Coturri, Dickson -- an ex-criminal defense lawyer from Houston, where he was born and raised -- has been making wine there since 2001.

What does Natural wine mean to Dickson? Grapes grown without the use of chemicals and vinified using native yeasts exclusively.

So what are native yeasts? Native or ambient yeasts are yeasts that occur and live naturally on the skins of the grapes, in the vineyards, and in the winery itself.

Fermentation -- the process whereby yeast transforms the sugar in grape juice into alcohol -- can be extremely difficult to control. In the period that followed the Second World War, European winemakers increasingly employed "cultured" yeasts, i.e., yeasts that had been grown in a laboratory in order to make wines more consistently and homogeneously. When you use yeast that occurs naturally, the process can be highly unpredictable: There can be a delay in starting fermentation; fermentation can get "stuck" (as we say in wine parlance); and unwanted yeasts can create undesirable aromas and flavors. Cultured yeast eliminates those problems.

In the 1970s, the California wine industry began to use cultured yeasts that would reliably deliver the exact same flavors in the wine -- sometimes regardless of the grape variety. Ever sipped a Prosecco that tastes like banana candy? Ever come across a Zinfandel that tastes like blackberry jam? Those flavors are the result of cultured yeast.

That's not to say that cultured yeast is a bad thing. In fact, the opposite is true. Many of the world's greatest winemakers employ "neutral" yeasts that allow them to control fermentation while permitting the native yeasts to do their work and ensuring that the wine will be an expression of "place."

And for a world driven by consumerism, of course, there is always a place under the sun for banana candy Prosecco, blackberry Zinfandel, and blueberry Malbec.

But winemakers like Lewis Dickson believe that their wines should be unbridled expressions of place and vintage. If Dickson's crop is attacked by insects or fungus and he is unable to contain the problems in the vineyard, he may very well lose an entire harvest of his fruit. If unwanted yeasts find their wine into his cellar during fermentation because he's not "yeasting" his wines (as the overwhelming majority of winemakers do today), he risks losing all of the contaminated vats or barrels.

Dickson takes it one step farther by choosing not to sulfur his wines. In other words, he never adds SO2 to his wines to stabilize them (as the overwhelming majority of winemakers do). This makes the wines more delicate and more difficult to ship. And it takes them much longer to stabilize and to settle. (See our post from last year on Wine and Sulfur Dioxide.)

On his farm in the Texas Hill Country, Dickson grows a handful of French grape varieties, as well as hybrids like Norton and (my favorite wine of his) Blanc du Bois. And he also grows Black Spanish, a variety that has been cultivated in Texas since the 1600s.

His wines are not available for sale retail in Houston, but he will ship within the state of Texas. And there are a number of his red wines on the list at RDG-Bar Annie on Post Oak.

I'm a fan of Dickson and his courageous wines. Whether you like them or not, you know you're tasting Texas when you drink them...